The fall of the Berlin wall caught the world by surprise. For months, East Germany's beleaguered communist rulers had tried in vain to silence a growing opposition movement and stem the tide of people pouring out of the country. On the night of Nov. 9, 1989, an East German official held a press conference to announce new government travel policies but inadvertently announced that crossings to the West would be opened "without delay." Within hours, thousands of East Berliners began lining up at checkpoints near the Wall. At first the border guards tried to check passports, but they quickly realized it...